import hashlib
import os
import uuid
from collections.abc import Generator
from contextlib import contextmanager
from typing import Final, LiteralString
from urllib.parse import urlsplit, urlunsplit

import psycopg
from psycopg import sql
from psycopg.rows import dict_row
from pydantic import JsonValue, TypeAdapter

ROWS: Final = TypeAdapter(list[dict[str, JsonValue]])


def read_rows(
    query: str, parameters: tuple[str, ...], *, database_url: str | None = None
) -> list[dict[str, JsonValue]]:
    with psycopg.connect(database_url or os.environ["DATABASE_URL"], row_factory=dict_row) as connection:
        connection.execute("SET TRANSACTION READ ONLY")
        return ROWS.validate_python(connection.execute(query, parameters).fetchall())


def advisory_lock_key(*parts: str) -> int:
    return int.from_bytes(hashlib.sha256(":".join(parts).encode()).digest()[:8], "big", signed=True)


def legacy_advisory_lock_key(text: str) -> int:
    return int.from_bytes(hashlib.blake2b(text.encode(), digest_size=8).digest(), "big", signed=True)


def advisory_waiters(lock_key: int) -> list[dict[str, JsonValue]]:
    unsigned: Final = lock_key & 0xFFFFFFFFFFFFFFFF
    return read_rows(
        "SELECT pid FROM pg_locks WHERE locktype = 'advisory' AND objsubid = 1 "
        "AND classid = %s::oid AND objid = %s::oid AND NOT granted",
        (str(unsigned >> 32), str(unsigned & 0xFFFFFFFF)),
    )


def write_rows(query: LiteralString, parameters: tuple[str, ...], *, database_url: str | None = None) -> None:
    with psycopg.connect(database_url or os.environ["DATABASE_URL"]) as connection:
        connection.execute(query, parameters)


@contextmanager
def scratch_database() -> Generator[str]:
    name: Final = f"integration_{uuid.uuid4().hex}"
    with psycopg.connect(os.environ["DATABASE_URL"], autocommit=True) as admin:
        admin.execute(sql.SQL("CREATE DATABASE {}").format(sql.Identifier(name)))
        try:
            yield urlunsplit(urlsplit(os.environ["DATABASE_URL"])._replace(path=f"/{name}"))
        finally:
            admin.execute(sql.SQL("DROP DATABASE {} WITH (FORCE)").format(sql.Identifier(name)))